The present invention relates to a water-based metallic ink composition and a writing instrument using the same.
The two-tone ink (double color ink), when writing is made with it, gives a two-tone color record consisting of a drawn line and a contour line bordering on either side thereof, thus enabling creation of variegated designs which cannot be realized with ordinary ink.
Heretofore known as the two-tone ink is a two-tone color ink composition comprising a metallic powder pigment, a water-soluble dye, water and a diffusible organic solvent for writing on a solvent-receptive substrate such as paper or cloth wherein the water-soluble dye penetrates into the substrate and diffuses around the drawn line derived from the metallic powder pigment to form colored borderlines (Japanese Unexamined Patent Publications 231777/1985, 123684/1986).
Two-tone color inks of this kind invariably depend on the dual coloration mechanism illustrated in FIG. 1 and the current main stream of the two-tone color ink composition employs two kinds of coloring matters, one penetrating into the substrate, e.g. paper, and the other not penetrating into the substrate, namely a water-soluble dye and a metallic powder pigment. Shown in FIG. 1 is a sectional elevation of the record. After writing, the water-soluble dye penetrates into the paper while the metallic powder pigment is deposited on the surface of the paper to give a two-tone record consisting of a central line derived from the metallic powder pigment and contour lines derived from the water-soluble dye and bordering on both sides of said central line (in the case of seeing the record).
In regard of drawn line records of this type, the recently diversified design needs call for the development of inks with which further unique lines can be written. For example, there exists a demand for written lines having borderlines comprised of a metal powder pigment, particularly a drawn record consisting of a central line derived from a colorant and contour lines derived from a metallic powder pigment and bordering on both sides of said central line.
However, with the conventional two-tone ink composition, all that can be drawn is a record consisting of a central line derived from a metallic powder pigment and a contour line derived from a water-soluble dye and bordering on either side of said central line, and there has not been developed an ink composition with which said new type of line can be drawn.
An object of the invention is to provide a water-based metallic ink composition which can give a record consisting of a central line derived from a formulated colorant and contour lines derived from the metallic powder pigment and bordering on both sides of the central line.
After an intensive investigation to overcome the drawbacks of the prior art, the present inventor found that an ink composition according to a herein-defined formulation accomplishes the above object and have perfected the present invention.
The present invention, therefore, is directed to a water-based metallic ink composition comprising a metallic powder pigment and a solvent characterized by its further comprising a poly(vinyl alcohol).
The present invention is further directed to a writing instrument using said water-soluble metallic ink composition.
The present invention is directed to a method of producing a record consisting of 1) a colorless or colored central line and 2) a contour line (contour lines) derived from a metallic powder pigment and bordering on either side (both sides)of said central line which comprises writing with the ball-point pen mentioned above.